1. Field of the Invention
The present invention relates to a plated terminal for connector, more particularly to a plated terminal for connector including an alloy plating layer, and a terminal pair formed by using such a plated terminal.
2. Description of the Related Art
Copper and copper alloy having high electrical conductivity, good ductility and appropriate strength are used for electrically conductive members used such as in electrical connection terminals. Since insulating films such as oxide films and sulfide films are formed on surfaces of these, contact resistance is high at the time of contact with other conductors. Accordingly, a terminal formed by applying tin plating 21 to a surface of a base material 22 such as copper or copper alloy as shown in FIG. 7(b) has been conventionally generally used as a connector terminal for connecting an electrical component or the like of an automotive vehicle. For example, a connector terminal including a tin plating layer is described in Japanese Unexamined Patent Publication No. H10-46363. As compared with other metals, tin is characterized by being very soft. In a tin plated terminal, a relatively hard insulating tin oxide film is formed on a surface of a metal tin layer. However, since the tin oxide film is destroyed with a weak force and the soft tin layer is easily exposed, good electrical contact is established.
In the connector terminal formed with the tin plating layer, good electrical contact can be established as described above due to the softness of tin, whereas there is a problem of a high friction coefficient at the time of terminal connection likewise due to the softness of tin. As shown in FIG. 7(b), on the surface of the soft tin plating layer 21, the tin layer 21 is easily dug up and easily adheres to itself when a connector contact slides. This increases the friction coefficient of the surface of the tin plating layer 21 and increases a force necessary to insert the connector terminal (insertion force). Particularly, in the case of using tin plating for terminals of a multi-pole fitting connector including many terminals, the insertion force becomes larger as the number of the terminals increases and a connecting operation becomes difficult.
The present invention aims to provide a plated terminal for connector and a terminal pair having a lower friction coefficient than a tin plated connector terminal.